Winfrey will be going up against herself on Thursday, here in New York, when she visits “The Ellen De Generes Show” (Ch. 4) at the same time “Oprah” is airing on Ch. 7. “Oprah” has steamrolled “Ellen” at 4 p.m. this season.

Ellen DeGeneres repays the favor by visiting “Oprah” this Monday, the day after her Oscar-hosting gig.

Jimmy Kimmel, mean while, is thisclose to inking a multi-year contract extension locking him in to ABC be yond 2009 – when Conan O’Brien is slated to succeed Jay Leno on NBC’s “Tonight Show.” The Kimmel exten sion, reported yesterday in Broadcasting & Cable, won’t nec essarily guarantee him the 11:30 p.m. slot (his show cur rently airs at 12:05 a.m.) – meaning he might not battle O’Brien di rectly. But, then again, there have been whispers NBC might stick with Leno beyond ’09 (which would force NBC to pony up a reported $40 million to O’Brien, according to B&C).

The “Leno Leaving in 2009” scenario was a head-scratcher from Day One, especially since workaholic Jay continues to enjoy a comfort able lead over David Letterman – and has never ex pressed any desire to retire. Read between the lines.

Last, but not least: * Everyman actor Chris O’Donnell had trouble get ting into The Plumm (Noel Ashman) last weekend – until he was finally recog nized. He partied with Marcus Schenkenberg.

* “Grey’s Anatomy” music supervisor Alexandra Patsa vas has created a songlist for cnbc.com, including tunes from The Dandy Warhols and Pharoahe Monch.